Speaker enclosure



June 2, 1964 H. E. BILL 3,135,348

SPEAKER ENCLQSURE Filed March 20, 1961 2 Sheets-Sheet 1 INVENTbR. Herert E B/'// A froeA/EYS June 2, 1964 H. E. BILL SPEAKER ENCLOSURE 2 Sheets-Sheet 2 Filed March 20, 1961 INVENTOR. Herber/ 6. 5/'// A rraew Y6 United States Patent 3,135,348 SIEAKER ENCLOSURE Herbert E. Bill, 2228 Dernington Drive,

Cleveland Heights, Ohio Filed Mar. 20, 1961, Ser. No. 96,959 24 Claims. (Cl. 18131) This invention relates to an enclosure device for speakers of the type used in reproducing audible sound waves. Such device is adapted for use with all types of sound propagating apparatus such as, for example, radio, phonograph, and television speakers, intercommunication, telephone, and public address speakers, or the speakers of electronic organs or similar musical instruments.

Generally it is an object of this invention to provide a speaker enclosure device which improves the realistic quality of electronically reproduced sound.

Another object of the invention is to provide such a speaker enclosure device which provides an increased volume for a given speaker size and power input.

A more specific object is to provide a speaker enclosure device having the above characteristics which effectively utilizes the energy which is expended in a rearward direc,-. tion from the speaker element in such manner as to reinforce and enhance the sound emanating in a forward direction.

Yet another object to provide a device of the above type which reproduces the realistic characteristics of a live performance by simulating the resonant sounds ordinarily heard which are actually waves of sound reflected from the walls and contents of the room or auditorium which surround both performer and audience.

Other objects of the invention and the invention itself will be understood from the following specification and the accompanying drawings, in which said drawings:

FIG. 1 is a front elevation of a firstembodiment of the speaker enclosure device of this invention; V

. FIG. .2 is a section taken along the line 22- of FIG. 1;

FIG. 3. is a top plan view of another embodiment of this invention; 7

FIG. 4 is a front elevation of the embodiment of FIG. 3;

FIG. 5 is a perspective view of still another embodiment of this invention;

FIG. 6 is a front elevation of a modified form of the embodiment of FIG. 5;

FIG. 7'is a front elevation of a modified form of the 7 this invention;

FIG. 9 is a top plan view of a final embodiment of the invention; and

FIG. 10 is an and elevation of the embodiment of FIG. 9.

Referring now to the drawings in all of which like parts are designated by 7 like reference numerals, the speaker enclosure device of this invention as illustrated in the embodiment of FIGS. 1 and 2 comprises a generally cylindrical housing 1 having a curved, C-shaped wall' 2. Said wall has circumferentially spaced, parallel edges 3 which define anopening at the front of the housing 1 which extends throughout the length of said housing. The wall 2 is preferably made of a rigid, sound reflecting material whereby it affords a concavely rounded, sound reflecting, inner surface 4.

A conventional loud speaker 5 is mounted in the opening between the circumferentially spaced edges 3 in such manner as to direct the sound from said speaker radially outwardly from the housing 1. The loud speaker 5 may begmounted across the opening in any suitable manner such as by channeled adapters 6 which fit over the edges .3 and provide opposed, coplanar slots 7 in which are firmly fixed elongated frame members 8. The frame 3,135,348 Patented June 2, 1964 members 8 are so spaced as to provide an opening equal in width to the normal effective diameter of the speaker cone, and said speaker is secured at the periphery thereof to the frame members by any suitable means such as small bolts as indicated at 9.

As best shown in FIG. 1, the resulting structure comprises a housing of substantially uniform section throughout its length having an elongated opening therein extend ing above and below the speaker 5 which is mounted across said opening. A conventional decorative screen or cloth 10 may be used to cover the opening and speaker if so desired, such screen or cloth being of a type which does not substantially interfere with sound which emanates from either the speaker 5 or the housing 1.

It has been found that the mounting of a loud speaker as above described has the effect of increasing the volume of the sound which is reproduced and giving it a realistic quality which is superior to that found in conventional speaker enclosure devices. The basic construction may be varied somewhat as indicated by the various embodiments and modifications exemplified by FIGS. 3 through 10. I For example, the embodiment of FIGS. 3 and 4 comprises a housing 20 having a curved, C-shaped wall 21 affording an opening between circumferentially spaced, parallel edges 22. Channeled adapters 23 are provided at the edges 22 in a manner similar to the first embodiment of the invention, said adapters providing means for mounting frame members 24 to which is secured a speaker 25. In this embodiment, it will be noted that a flat bafiie board 26 is mounted in the rear of the housing 20 diametrically opposite the speaker 25. The purpose and function of said bafiile board will be herein later fully discussed in connection with the operation of the invention and a proposed theory of such operation.

The embodiment of FIG. 5 comprises a housing 30 having a circurnferentially continuous, generally cylindrical Wall 31 provided with an irregular aperture 32 which perforates said wall and a part of which is adapted to receive a speaker 33 as indicated at 32a. Closure members 34 are provided at the ends of the housing, and a portion of the aperture 32 remains unobstructed as indicated at 3212.

FIG. 6 shows a modification of the invention which is substantially similar to the embodiment of FIG. 5, FIG. 6 illustrating a hollow, substantially cylindrical speaker enclosure housing having end closure members 41 and an elongated, noncircular aperture 42 in thewall of said housing. In this instance the axis of the housing 40 is horizontally disposed, a position which may be preferred in some installations and which positioning does not effect the operation of the invention. A speaker 43 is mounted within the aperture 42 in any suitable manner whereby it is adapted to direct the sound therefrom radially outwardly from the housing 49 in the manner as set forth in connection with the previous embodiments. It will be noted that the aperture 4-2 is substantially larger than the speaker 43 thereby allowing free release in a forward direction of sound from within the housing.

The illustration in FIG. 7 is an adaptation or modification of the embodiment of FIGS. 1 and 2 wherein a plurality of speakers of different size and frequency range are mounted unitarily within a single housing of the present invention. FIG. 7 shows a substantially cylindrical, hollow housing 50 which is generally C-shaped in section, similar to the showing of FIG. 2, wherein the opposed edges of the wall, indicated at 51, are provided with adapters 52 which securely hold frame members 53. Said frame members are progressively inwardly stepped at 54, 55, and 56 from the bottom of the housing upwardly, and said steps are so complementary as to define an opening throughout the length of the housing having portions of for mounting a relatively large, bass speaker 57; the relatively narrower portion as indicated at 55a provides means for mounting a pair of speakers 58 and of intermediate frequency range; and the portion 56a provides means for mounting a pair of high frequency speakers or tweeters 60 and 61. It will be noted that each portion of the opening is of such width as not to obstruct the speaker or speakers mounted therein and that considerable space is provided above and below each speaker to allow for the free passage of sound from within the housing 59.

The showing of FIG. 8 illustrates an adaptation of the present invention wherein there is provided a housing '70 having a wall portion 71 which is generally U-shaped in section providing a concavely rounded inner surface at the back of the enclosure as indicated at 72 and generally parallel, partially curved side wall surfaces 73 projecting forwardly an equal distance therefrom. The forwardly directed edges of the wall portion '71 are connected across the front by a flat front wall portion 74 having an elongated aperture 75 therein. The aperture 75 is generally rectangular in shape as herein illustrated, andintermediate the ends of the longer sides it is arcuately notched as indicated at 76 to receive a speaker 77 mounted therein in any suitable manner. The aperture 75 extends well beyond the speaker 77 in either direction, and no end closure members are used in this embodiment.

The final embodiment of FIGS. 9 and shows a speaker enclosure comprising a curved housing 80 having agenerally cylindrical or C-shaped wall 81 which is uniform in section throughout its length with the exception that the ends thereof are provided with symmetricaltapers as indicated at 82. The wall 81 terminates in either circumferential direction in spaced, opposed, parallel edges 83 which are at the front of the housing 80, and the tapers 82 are convergently directed rearwardly or toward the back of said housing. The tapered ends are closed by means of closure members 84 which provide flat, obliquely outwardly directed reflecting surfaces 84:: at either end of said housing.

The opposed edges 83 provide therebetween an enlarged opening 85 in which is suitably mounted a speaker 86. Said speaker is preferably disposed centrally intermediate the ends of the housing 80 with the front of said speaker being coplanar with the front of said housing. As in the previous embodiments, it will be noted that the opening 85 is substantially larger than the speaker 86 which is mounted'therein.

It is anticipated that the speaker enclosure housings as above described may be readily mounted upon axes for rotation about the normal axes. of the individual housings in such manner as to be rotatable for varying the direction from which the sound is propagated. The generally circular configuration of the housings make them particularly adaptable for this refinement in use of the invention. It is further anticipated that the individual distinctive features of the several embodiments and modifications, such as the open or closed ends, tapers, baflle board, or the like, may be interchangeably utilized with other'embodiments and modifications if so desired.

The speaker enclosure housing in all of the forms shown is preferably made of a rigid material which provides a sound reflecting inner surface; Materials such as wood, metal, or ceramic provide extremely satisfying results. Ceramic material has proved to be outstandingly successful in that it combines the required rigidity and I sound reflecting surface with substantial weight and l increasing the apparent volume of the sound and giving it an increased realism which effectively simulates the effects of a live performance. It is believed that the volume of the reproduced sound is increased due to the fact that sound waves emanating from the rear surface of the loud speaker are reflected from the inner, concave surface of the housiing and projected forwardly through the opening in the housing around the speaker or speakers thereby utilizing energy which is expended in a rearward direction from the speaker and adding it to that which normally emanates from the speaker in a, forward direction. It has been found that there is no distinguishable time lag in the sounds thus reflected whereby they might interfere with the sound coming from the front of the speaker. The sound waves which originate in the rear surface of the vibrating element of the speaker project rearwardly into the housing in all directions, and it is felt that these sound waves are reflected from the inner surface of the housing wall at angles equal to those at which said waves impinge on any point of the inner surface of the housing. The sound waves are thus reflected. individually in different directions and the curved walls of the housing so diffuse these reflected waves that they cannot acquire a concentration sufficient to audibly interfere with the sound projected forwardly from the speaker.

Some of the'sound waves reflected from the inner surface of the housing generally opposite the opening or aperture in the housing are reflected forwardly through such opening thereby'adding to the volume of the sound transmitted in the manner suggested. Other sound Waves which do not escape through the opening in the housing are reflected back and forth against opposite inner surface portions, and the fact that these waves are reflected at individually different angles and that the enclosure is not entirely closed makes it impossible for an accumulation of sound waves in the same phase and direction to occur with suflicient concentration to distort the audible sounds or dampen the vibration of the speaker. The opening in the housing, part of which is unobstructed by the speaker front thereof. It has been found that the enclosure may be used with satisfactory results with either the ends closed or open provided there is suflicient opening at the front of the enclosure in excess of that obstructed by the speaker or speakers.

The increased quality of the reproduced sound is believed to be the result of a reproduction or simulation of overtones which are actually part of the audible sound originally made in a live performance and which part constitutes sound waves reflected from the walls and contents of the room or auditorium which surrounds the performer. The reflected waves within the cabinet are realistically similar to these waves, and the result is an added resonance or depth which is not obtained in conventional speaker enclosure devices.

The extent of the curvature of the inner surface of the housing may be varied, but the best effects are obtained if such curvature is at least substantially one-half of the area of the chamber walls. Such curvature may be either cylindrical or noncylindrical; for example, the housing may be elliptical in section if so desired. The location of the curvature can be at either the front or the rear of the housing but preferably includes a substantial portion of the side surfaces. The baffle 26 0f FIGS. 3 and 4 gives to the housing Ztlthe effect of a flat, rear reflecting surface which may be used to assist in projecting the reflected sound forwardly through the opening in the housing wall 21. Such bafile board is preferably substantially a width equal'to the diameter of the speaker cone and approximately equal to the opening in the housing wall.

The opening or aperture in the front of the housing may be of various shapes or'sizes having an area substantially greaterthan that covered by the speaker or speakers to be mounted therein. The electronic apparatus necessary for sound reproduction other than the speaker itself, such as a radio, phonograph turntable, amplifier, or the like, can be mounted within the housing if desired, preferably above or below the speaker. Such apparatus may also, of course, be mounted separately from the speaker enclosure itself. It is anticipated that in some applications of this invention a separate lining inside the housing may be used to vary or modify the amount or degree of reflectivity of the sound. 7

It will be understood that the illustrations of speaker enclosures as hereinpresented are given as examples only of practical applications of the principle of this invention and that many changes in the details thereof may be made without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

l. A speaker enclosure device comprising a hollow housing having a sound reflecting inner wall surface; said surface being of substantially uniform sectional contour throughout one dimension; a substantial portion of said inner wall surface being concavely rounded; means defining in opening in said housing; speaker means mounted in said opening in such manner as to normally direct sound therefrom outwardly away from said housing; said opening being larger than said speaker means.

2. A speaker enclosure device as set forth in claim 1 wherein the rounded portion of the recited wall surface comprises at least substantially one-half of the area of said inner wall surface.

3. A speaker enclosure device as set forth in claim 2 wherein the rounded portion of the recited wall surface includes a substantial portion of that part of said wall surface which is disposed on either side of said speaker means.

4. A speaker enclosure device comprising a hollow housing having a rigid, sound reflecting wall of uniform thickness defining said housing; said housing being of substantially uniform section throughout its length; a substantial portion of said wall being rounded in such manner as to provide concavely rounded inner wall surface portions; means defining an opening in said wall; speaker means mounted in said opening in such manner as to normally direct sound therefrom outwardly away from said housing; said opening being substantially larger than said speaker means.

5. A speaker enclosure device as set forth in claim 4 wherein the recited rounded portion of said wall comprises at least substantially one-half of said wall.

6. A speaker enclosure device as set forth in claim 4 wherein the recited opening in said wall extends substantially through said wall in a direction parallel with its length.

7. A speaker enclosure device as set forth in claim 4 wherein the recited wall is substantially C-shaped in section; said means defining said opening comprising spaced, parallel, longitudinal edges of said wall.

8. A speaker enclosure device as set forth in claim 4 wherein the recited wall is substantially C-shaped in section; said means defining said opening comprising spaced, parallel, longitudinal edges of saidwall; and a flat bafile board mounted within said housing behind and spaced from said speaker means.

9. A speaker enclosure device as set forth in claim 4 wherein the recited wall defines a substantially peripherally continuous closed housing having .concavely rounded inner wall surfaces at every portion of the periphery thereof; and closure members closing the ends of said housing.

10. A speaker enclosure device as set forth in claim wherein the recited wall is substantially C-shaped in section; said opening extending throughout the length of said wall; means defining spaced portions of varying width throughout said opening; said speaker means comprising a plurality of speakers of different sizes mounted in spaced portions of corresponding widths.

' 11. A speaker enclosure device as set forth in claim 4 wherein the recited wall comprises a generally U-shaped wall portion affording a conclavely rounded back wall surface and generally parallel side wall surfaces; a flat wall portion connecting the ends of said U-shaped Wall portion; said opening being disposed in said flat wall portion.

12. A speaker enclosure device comprising a hollow, substantially cylindrical, open-ended housing; said housing being made of rigid, sound reflecting material; means defining an opening in said housing; speaker means mounted in said opening in such manner as to normally direct sound therefrom outwardly away from said housing in a radial direction; said opening being larger than said speaker means.

13. A speaker enclosure device as set forth in claim 12 wherein the recited opening in said housing extends in an axially parallel direction completely through the wall of saidhousing.

14. A speaker enclosure device as set forth inclaim 12 including closure means closing the ends of said housmg.

15. A speaker enclosure device comprising a hollow housing having a substantially cylindrical, open-ended wall defining said housing; said wall being made of rigid, sound reflecting material; said wall circumferentially separated at one point in the circumference thereof and having means providing spaced, opposed edges; said edges being complementarily stepped and providing an opening in said wall having spaced edge portions of varying widths; a plurality of speakers of different sizes and frequency ranges mounted between spaced edge portions of corresponding spaced widths; said plurality of speakers mounted to saidhousing in such manner as to normally direct sound therefrom outwardly away from said housing in a radial direction; said spaced edges defining an opening in said wall which is larger in area than the combined area covered by said speaker means.

16. A speaker enclosure device comprising a hollow, open-ended, substantially cylindrical housing made of ceramic material; means defining an opening in the curved wall of said housing; speaker means mounted in said opening in such manner as to normally direct I than said speaker means; and a flat baffle element positioned in said housing diametrically opposite and spaced from said speaker means.

18. A speaker enclosure device comprising a hollow, substantially cylindrical housing; means defining an opening in said housing; speaker means mounted to said housing across said opening in such manner as to normally direct sound therefrom outwardly away from said housing in a radial direction; said housing having rearwardly convergent, tapered ends; closure members closing said tapered ends; said opening being larger than said speaker means.

19. A speaker enclosure as set forth in claim 18 wherein the recited housing comprises a substantially C- shaped wall; said means defining said opening comprising spaced, parallel, longitudinal edges of said Wall.

20. A speaker enclosure device comprising a hollow housing having a sound reflecting inner wall surface; said surface being of substantially uniform sectional contour throughout one lineal dimension; said Wall surface being generally U-shaped and affording a concavely rounded back wall surface portion and generally parallel side wall surface portions; a generally flattened, front wall disposed across the ends of said U-shaped surface; speaker means mounted in said front wall in such manner as to normally direct sound therefrom outwardly away from said front wall; and means defining opening means in said front wall whereby sound reflected from said U-shapcd surface is directed forwardly from said housing.

. 21. A speaker enclosure device comprising a hollow housing having a generally U-shaped, concavely rounded, inner wall surface; said surface being of uniform sectional contour throughout one dimension; a flat front housing having a rigid, semicircular, U-shaped, sound refleeting wall of uniform thickness; a flat front wall disposed across the ends of said U-shaped Wall; said housing being of substantially uniform cross section throughout its length; speaker means mounted in said front wall in such manner as to normally direct sound therefrom forwardly A speaker enclosure device comprising a hollow housing having a generally U-shaped, concavely rounded, inner wall surface; said surface being of uniform sectional contour throughout one dimension; a flat front wall bridged across the ends of said U-shaped surface; means defining an opening in said front wall; speaker means mounted in said'opening in such manner as to normally: direct sound therefrom outwardly away from said housing; said opening extending beyond said speaker in at least one direction.

24. A speaker housing having a U-shaped, sound re-s fleeting wall comprising three side portions of said housing; at least the central portion of said ,U-shaped wall being rounded in transverse section; a flat front Wall bridged across the ends of said U-shaped wall; said housing being of uniform transverse section throughout one lineal dimension; speaker means mounted in one of said walls in such manner as to normally direct sound outwardly away from said housing; and means defining opening means in said one wall directing sound outwardly from said housing in the same direction as said speaker means.

Referentes Cited in the file of this patent UNITED STATES PATENTS 

1. A SPEAKER ENCLOSURE DEVICE COMPRISING A HOLLOW HOUSING HAVING A SOUND REFLECTING INNER WALL SURFACE; SAID SURFACE BEING OF SUBSTANTIALLY UNIFORM SECTIONAL CONTOUR THROUGHOUT ONE DIMENSION; A SUBSTANTIAL PORTION OF SAID INNER WALL SURFACE BEING CONCAVELY ROUNDED; MEANS DEFINING IN OPENING IN SAID HOUSING; SPEAKER MEANS MOUNTED IN SAID OPENING IN SUCH MANNER AS TO NORMALLY DIRECT SOUND THEREFROM OUTWARDLY AWAY FROM SAID HOUSING; SAID OPENING BEING LARGER THAN SAID SPEAKER MEANS. 